Isomaltulose (also referred to as Palatinose®) is a disaccharide with α-1,6-glycoside linking of glucose and fructose (6-O-α-D-glucopyranosyl-fructofuranose). Isomaltulose is used in the food industry and pharmaceutical industry as a sweetener, vehicle and/or filler. An important area of application of isomaltulose is use of sucrose. Isomaltulose is often stored and processed like sucrose or other sugar substitutes in crystalline form as a loose bulk product. Crystalline isomaltulose, if possible, should have good storage capability and flow properties like other sugar substituents, in order to be fed to processing installations suitable and adapted for such substances without requiring major processing adjustments or design changes to the installations.
In contrast to other crystalline sugar substitutes isomaltulose is not very hygroscopic; high storage stability is expected accordingly. Unexpectedly, however, isomaltulose exhibits the disadvantageous effect of so-called “long-time compaction.” In this phenomenon the isomaltulose crystals “cake together” to clumps or agglomerates. Such clumps or agglomerates hamper the flowability of the product during further processing. For example, isomaltulose is stored in sacks or so-called big packs and the content of the sacks fed to mechanical processing via filling hoppers or chutes. The formed agglomerates hamper emptying of the sacks and prevent flowing of the bulk product into the filing hoppers. Additional mechanical processing steps are therefore generally necessary in order to feed the stored and agglomerated isomaltulose to mechanical processing.
As an alternative, isomaltulose is stored in bulk product silos. Long-time compaction also occurs there. Isomaltulose therefore has a tendency toward shaft formation in core-flow silos. Silo storage of isomaltulose is seriously hampered and inexpedient in specific types of silos. Additional measures must be taken during silo storage, like periodic circulation within the silos.
Systematic studies show that massive long-time compaction occurs already after short storage times of about 48 hours. It was also found that further lengthening of the storage time over several days (for example 240 hours) only slightly increases the initial extent of long-time compaction. In comparison with other bulk products that are also known to have a tendency to agglomerate over time, the long-time compaction in isomaltulose occurs very quickly as a disadvantage. Long-time compaction of isomaltulose is also essentially independent of the usual moisture content of stored isomaltulose and the usual storage conditions. Moisture content and storage conditions disadvantageously do not have a sufficient effect on long-time compaction and flowability of isomaltulose. No ordinarily available storage conditions are known in which the undesired long-time compaction is adequately reduced.
There is a demand for obtaining crystalline isomaltulose as a bulk product in flowable and silo-storable form without disadvantageous long-time compaction occurring during storage.
In order to obtain flowability of bulk products for storage and processing in the food industry and in pharmaceuticals, so-called anticaking agents are generally added. Known anticaking agents include silicates, aluminosilicates, polysiloxanes, phosphates, sodium hydrogen carbonate or starch powder. A shortcoming of these auxiliaries is that they contaminate the initial product and/or have chemical properties that lead to drawbacks during processing of the product. It is also essential to declare such auxiliaries in the finished food product or pharmaceutical product.